The requirements of extended capacity and increased reliability associated with data communication environments that allow convergence of voice, data and video, as well as storage on IP networks has created a need for carrier-class availability. Carrier-class infrastructure, also known as “carrier grade” infrastructure, is considered a relatively reliable network hardware and software infrastructure. Enterprises such as mobile wireless carriers, data access providers, and fixed wireless carriers, as well as enterprises and government institutions that operate broadband wireless networks often use carrier-class infrastructure for handling their IP communications and mission critical applications. For example, to carry voice traffic and real-time traffic in converged environments, a carrier-class network infrastructure may be configured to deliver the same level of availability as the public switched telephone network. Thus, in establishing a carrier-class infrastructure, the communications network can be deployed with topology designed to suit the needs of the particular enterprise.
A network topology is the pattern of links between nodes where a given node has one or more links to other nodes in the network. Physical topologies of networks include examples such as ring, mesh and bus. A logical topology is the nature of the paths that signals follow from node to node, and, in many instances, the logical and physical topologies are similar.
For increased bandwidth, load balancing and availability of communication channels between nodes (e.g., switches and stations), link aggregation or trunking, according to IEEE standard 802.3ad, is a method of grouping physical network links into a single logical link. With link aggregation, it is possible to increase capacity of communication channels between nodes using their Fast Ethernet and Gigabit Ethernet technology. Two or more Gigabit Ethernet connections can be grouped to increase bandwidth, and to create resilient and redundant links. Standard local area network (LAN) technology provides data rates of 10 Mbps, 100 Mbps and 1000 Mbps and, for obtaining higher capacity (e.g., 10000 Mbps) link aggregation allows grouping of 10 links. Where factors of ten (10) are excessive, link aggregation can provide intermediate rates by grouping links with different rates.
Wired network protocols are designed to meet the Ethernet set of requirements and aim to improve scalability, bandwidth allocation and throughput in order to meet the demands of packet-switched networks. A typical Ethernet physical layer interface presently meets 1 Gbps to 10 Gbps rates. In the event of fiber or node failure, recovery may need to satisfy 50 milliseconds recovery time.
Current carrier class infrastructure requirements deal with quality of service (QoS), resiliency, reliability, load balancing, response time and manageability of the communications network. Standards establishing these requirements are designed for QoS at a particular level. However, providing load balancing at layer-2 or layer-3, for instance, is difficult because it depends on upper-layer features of the traffic. Additionally, the recovery time during which a system folds back into a valid configuration takes too long, creating a convergence problem.